What was the purpose of black codes during reconstruction

Which was the cause of the rise of the persian empire?

What is zinn's approach to the study of history? what does he suggest occurs when history is told is the story of human progress?

President nixon resigned from office in 1974 after he was informed that the senate would impeach him, as allowed in the constitution, for his actions in the watergate scandal. one of the key reasons that nixon’s actions became public was a) the freedom of press guaranteed by the first amendment. b) the right to confront witnesses as guaranteed by the sixth amendment. c) the limitation of judicial powers as defined in article 3 of the constitution. d) the prohibition against illegal search and seizure as guaranteed by the fourth amendment.